All of the advice listed here is the result of my personal experience. There are many different ways to set up tanks, etc. but I can only write about what has worked for me.This advice is intended to help out beginners to the dart frog hobby, but lots of additional information is available on the web.

Vivarium setup
The way I setup my vivariums I start with a basic drainage layer. This consists of 1-2 inches of either river gravel, aquarium pea gravel, or clay pellets. Some people use false bottoms, but I believe it is more work then it’s worth. In all of the tanks, to provide easy drainage, we have either tubing in the corner to use as a siphon, or a spigot.
Then there is a medium layer consisting of terra mix. I make my own terra mix which is composed of woody materials including orchid bark, coconut chips, treefern root and spongy materials consisting of sphagnum moss, coco peat, and sheet moss and other materials including leaves (for beneficial bacteria, I use oak, and avoid leaves that turn to mush such as maple) and moss. It is available on the dry goods page.
On top of this I place a layer of moss that acts as a good cover and takes care of the waste.
Depending on the type of frog (see below for specific types of vivaria) I then place plants in the tank. I use slow growing plants such as Pincusion philodendron for open floor vivarium (Type 1). I use fast growing broad leaf plants such as Pothos for the type 2 and 3 vivaria.
Cork bark on top of the moss provides a nice shelter and hiding place for all dart frogs. A soak dish is also needed in the tanks.
All of the tanks contain glass tops. This keeps the humidity high, but you must monitor humidity depending on the seasonal changes. Humidity may be high as 80% in the summer and get down to 10% in the winter because of home heating.

There are four basic types of vivariums I set up, based on the types of frog I need to house.
Type 1 Open Floor vivariums are good for terriblis, bicolors, tinctorius, and azureus. This type of tank provides lots of visibility.
Type 2 Canopied vivariums have lots of plants and leaf litter for tricolor, vittatus, auratus, leucomelas, galactonotus and aurataenia. The canopy provides a cover for these frogs that like to have something over their heads, yet allows the owner to be able to see the frogs from the front of the tank. As mentioned I often use pothos plants, which provide a wide cover.
Type 3 Tall vivariums are used for the thumbnail dart frogs that are nonegg-feeders. A tall tank is used that contains various plants, including some bromeliads. The humidity is kept high. Plants are also bunched up in the corners or along the back wall to create egg-laying spots for breeders.
Type 4 Eggfeeder tanks are used, as suggested, for all the eggfeeder dart frogs. These tanks are mostly open except for bromeliads dispersed in the tank.

Vivarium size
Tank size is controversial. It all comes down to personality, socialization skills programmed in their upbringing, tank design, and number of each sex. I’ve had azureus that fight like mad when more than 1 of each sex is placed in the same tank. At the same time I’ve had 3 males and 1 female dwarf tinctorius breed well living all in the same vivarium. This group of 4 dwarfs was purchased from a store where they had been raised together with 4 others in a 55 gallon tank. I recently sold 2 male dwarfs that had been raised in a group of 6 adult males that never wrestled. When these 2 males were put into a new terrarium they started wrestling. Possibly they were 2 subdominant males that started to fight over this new territory.
Depending on the species and tank design a general rule is 1 dendrobate per 5 gallon tank and 1 phyllobate per 10 gallon tank. Two frogs can be raised (again depending on species, sex, and terra design) for dendrobates in 10 gallon tank or bigger, and for phyllobates in 20 gallon tank or bigger.
Since there are so many variables in housing frogs together the best advice is to watch the frogs for aggression and bullying and have an extra tank set up to remove the bullied frog before its health is affected.

Mixing species
As far as mixing species goes….I can’t recommend it. I hear plenty of success stories about mixing species, but there are no golden rules and many consider dart frogs too much of an investment to experiment in this way. Some people have kept azureus and terribilis with red efts , salamanders, white's tree frogs, uroplatus geckos etc. etc. etc. This may be successful because of the mixing of nocturnal and diurnal habits of the species. If you have a big enough vivarium and want to mix species most success stories involve auratus/leucomelas or azureus/tinctorius cohabitation. Again, the best advice is to have a backup tank to remove frogs if bullying occurs.

Feeding/Cultures
The difficulty of feeding dart frogs is likely the reason dart frogs haven’t exploded in popularity. Dart frogs eat small food items that many pet supply stores don’t carry.
Fruit flies are the staple of the dart frog diet. Most other insects outgrow feedable size too quickly. There are a set number of fruit flies to feed to a certain size frog under certain conditions and temperatures but that would be too difficult to explain in this web page. Generally, you want to keep the weight of your frog at a “healthy level”, so feed more or less to maintain that weight. Take a look at the pictures on my web site to get a feel for what this “level” is.
Fruit fly cultures produce more or less flies per day depending on how many flies you start with and the quality and amount of medium used. My cultures last about 3 to 7 weeks and produce a good number of flies if kept moist that long. Medium drying out will shorten the life of a culture, because the larvae and pupae desiccate. Pinhead sized crickets are also used to feed dart frogs. My adults eat up to 3/16th size crickets. I feed them sparingly since the mineral ratio isn't as ideal as fruit flies. All food must be dusted to provide vitamins and minerals. You want the vitamins and minerals to be seperate...and you mix them right before you dust. I dust with a mixture of Repcal and Herpta-vite, it works best for the way I feed. Other foods include termites, springtails, waxworms, sow bugs, wood lice, aphids, spiders, ants etc etc.. All have their advantages and drawbacks to culturing and feeding.